The “Lost and Found” folder

A book gets put in Lost and Found in three scenarios:

1. When Joining an existing Team Collection, Bloom finds that there is already a Working collection by the same name and it contains a book with the same book ID as one in the Shadow collection but a different name.
2. When Joining an existing Team Collection, Bloom finds there is already a Working collection by the same name, and it contains a book with the same name as one in the Shadow collection but a different book ID.
3. When Syncing a Team Collection, Bloom finds a book that is checked out and edited in the Working collection, but is recorded in the Shadow collection as being: a) checked out by you elsewhere, or b) checked out by someone else, or c) checked in but edited and changed in any way.

#3b will create a NotifyUserOfProblem, allowing the user to report it.

#1 and #2 represent somewhat unusual circumstances, but not necessarily a failure of our code.

#3a and #3c probably indicate some failure of the checkout/checkin system, though it could be something else (e.g., someone unwisely restored an old backup of the Dropbox folder).